Method and apparatus for producing oil from solids



N0 14, 1961 w. J. cuLBERTsoN, JR 3,008,894

METHOD AND APPARATUS FOR PRODUCING OIL FROM SOLIDS Filed May 20, 19.58 2Sheets-Sheet 1 WJ" xm/:mp5s

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3,008,894 METHOD AND APPARATUS FR PRGDUCING OlL FROM SOLDS William J.Culbertson, Jr., Denver, Colo., assignor, by

mesne assignments, to The @il Shale Corporation,

Beverly Hills, Calif., a corporation of Nevada Filed May 20, 1953, Ser.No. 736,497 34 Claims. (Cl. 208-11) This application relates toapparatus and processes `for producing oil and gases from solidmaterials leaving a carbonaceous residue after pyrolysis and relateparticularly to apparatus and contiguous processes for producing crackedoils from such so-lid materials as oil shale, tar-sand, peat, etc. Theterm carbonaceous residue denotes a residue which includes xedcombustible carbon.

inasmuch as solid materials, such as oil shale, are found Some distancefrom the relinery centers, it is extremely desirable to thermally crackthe oil in such a manner as to reduce its viscosity and/or pour pointprior to its introduction into a pipe line for ease in transportation.Such a thermal cracking is sometimes referred to as visbreaking, or ifthe cracking is prolonged, as coking.

Often it is desirable to thermally crack such materials as liquid shaleoil after they are produced from solids by pyrolysis or retorting butbefore they are hydrogenated. Such a cracking step reduces the tendencyfor coke to be laid down on the hydrogenation catalyst and in otherparts of the hydrogenation `apparatus and reduces the frequency ofshutdowns for its removal.

It is also desirable in some cases to crack oils at rather hightemperatures after they are produced from solid materials by pyrolysisin order to obtain useful chemicals and intermediates.

While thermal cracking of shale oil or of oil vapors and gases from suchsolid materials as oil shale, in combination with a pyrolyzing step, isdeiinitely desirable, certain problems are incident to the combinedpyrolyzing and cracking process. One of the problems encountered is thefollowing: as the thermal cracking of the oil vapors and gases occurs,coke and tarry substances are produced, the presence of coke and tarbeing one of the main causes of eventual shutdown of the cracking phaseof the process. For these coke and tarry residue products will clogvital parts of the cracking equipment, and may also cause overheatingand possible' bursting of the equipment. The cost of shutdown isextremely great and is therefore to be avoided.

A second problem encountered is that of dust formation in the pyrolysisstep, the dust, in the usual prior art processes being entrained withthe oil vapors and gases leaving the pwolysis phase of the process, theprior art requiring the use of dust-separating equipment for theremoval.

Bearing in mind the foregoing facts, it is a major bject of the presentinvention to provide a simpliiied and economical continuous process forthe combined pyrolysis and thermal cracking of solid materials, whichleave a carbonaceous residue, upon pyrolysis.

It is another major object of this invention to provide au overallprocess wherein increased thermal eiciency is realized by combiningpyrolyzing and thermal cracking operations, without condensation of theoil product prior to the cracking operations.

Another major object of the present invention is to provide in acombined pyrolyzing and cracking process an efficient, simple andinexpensive method of removing coke and tar as it is produced in thecracking phase yof the process, thereby substantially reducing the needfor shutdown, cleanout, and other attendant problems.

nited States Patent 0 Mice provide a combined pyrolyzing and crackingprocess for solid materials, such as oil shale and the like, whereincoke produced during a thermal cracking stage is burned to provideadditional heat for use in the retorting process, or for other purposes,resulting in an overall increased thermal eiiciency, and wherein themore volatile tars produced during the thermal cracking stage are gasiedand cracked, resulting in a greater overall yield of valuable crackedoil and gases.

Still another object of the present invention is to provide a processwherein dust particles, resulting from the pyrolyzing operation, areseparated from the crude oil vapors andy gases in an improved andsimplied manner, which considerably reduces the necessary capacity ofdust-removal equipment, usually required, and in many instances,completely eliminates the need for such dustremoval equipment.

These and other objects of the present invention will be more clearlyunderstood by referring to the following description, and to theaccompanying drawings, in which:

FIGURE 1 is a schematic ilowsheet of one form of my process;

FlGURE is a schematic ilowsheet of a modiiied form of my process; and

FIGURE 3 is a iiowsheet of a second modied form of my process showingpossible forms of `apparatus that are employed.

In general, my combined pyrolyzing and thermal cracking continuousprocess employs one or more streams of hot heat-transfer bodies for thefurnishing of substantially all of the heat requirements of the process.It is found that the use of such circulating heat bodies in the combinedpyrolyzing and cracking process, to be described, is the primary reasonfor the substantial reduction in clogging and overheating of thecracking equipment, due to coke and tar formation, and is the primaryreason for the substantial removal of dust from the oil vapors and gasesproduced in the process.

Referring now to FIGURE 1, the process will be described with particularreference to oil shale. Fresh yoil shale -or the like continuouslyenters a preheating zone 10, along the line 12, at ambient temperatures.The fresh oil shale is intimately commingled with a plurality ofsubstantially hotter heat-carrying bodies continuously entering thepreheating zone along .the line 14 rat a temperature usually lyingbetween approximately -800 `and 1000 F. The substantially hotterheat-carrying bodies are hard, wear-resistant and heat-resistant, andare made, for example, of steel, metal alloys, or ceramic materials.These bodies are generally spherical in configuration and will besometimes referred to hereinafter as balls.

the oil shale commences to become sticky or gummy' and it is undesirablefor this condition to exist in .the preheated, while avoiding theabove-described disadand transporting lmaterial in such condition toother steps of the process. With some types of oil shale, the

- upper temperature limit to which the oil shalecan be Still a furtherobject of the present invention is to preheated, while avoiding theabove-described disadvantages, is approximately 700 F.

The ball size is generally somewhat larger than the average inlet oilshale size, and is of the order of 1% of an inch to one inch. The oilshale may then be separated from the balls, after the preheating step,by standard screening methods or by other suitable means, such as byelutriation. The oil shale leaves the preheating zone continuously alongthe line 13 and is fed directly to the pyrolyzing step in zone 20.

The balls, which are now considerably cooled and have a temperaturelying between approximately 450 and 700 F., are sent, via line 22, to aball heating step in zone 24. The balls are heated in the ball heatingzone 24 by means of products of combustion of the carbonaceous residueof the oil shale and of coke and non-volatile tars producing during thecracking, as will be described more fully. The ball temperature, afterreheating, preferably lies between 1000 and l400 F. All of the very hotballs are removed from Zone 24 via line 2S. All or part of these everyhot balls are then introduced into the pyrolyzing zone 20 via line 26and are intimately commingled, in parallel flow, with the preheated oilshale.

Part of the hot balls may by-pass the pyrolyzing zone 20 completely,being sent to the cracking zone 30 via lines 27 and 32. The amount ofhot balls by-passing the pyrolyzing zone 20 varies greatly from a zeroamount to approximately 50% of the total balls ernployed, depending onthe temperatures desired in both the pyrolysis and cracking zones 20 and30, respectively. The by-pass feature will be described in more detailhereafter. The process Will be confined, for the present, to a zeroby-pass, that is to say, to a process wherein the entire amount ofcirculating balls passes through the pyrolysis zone 20. The pyrolyzingphase of the process is preferably conducted in a horizontal or inclinedrotating drum similar to the pre-heating drum.

Counterflow of balls and oil shale may also be used, although this modeof heat transfer is not presently preferred.

The oil shale is pyrolyzed, by contact with the hot balls, the oil vaporand gas effluent, leaving the pyrolyzing zone 20 along the line 28, tobe sent directly in the vapor phase, to the cracking step in zone 30.The temperature of the pyrolyzed oil vapors and gases usually liesbetween 750 and 950 F., The oil vapors and gases may have a small amount(of the order of several percent) of liquid suspended therein. However,for purposes of this application, such a vapor, with very small amountsof liquid, will be referred to as a vapor phase.

All of the circulating balls, which are now cooled to a temperature ofbetween 850 and 1050 F., are sent directly from the pyrolysis zone 20 tothe cracking zone 30 via line 32.

The cracking preferably occurs in the vapor phase at substantiallyatmospheric pressure. The 750 to 950 F. oil vapors and gases Contact the850 to l050 F. balls directly for a predetermined period of time, e.g.,from 20 seconds to 2 minutes, and a cracking of the oil vapors and gasesresults. The balls, oils and gases, can contact each other either incoow, counterflow or crossflow in the cracking zone 30, the counterflowmode of operation being shown schematically in FIG- URE l.

The cracked oil vapors and gases leave the cracking zone 30, via theline 34, having a temperature of approximately 825 to 1000 F., to besent to further process steps such as quenching, condensation, etc., inpreparation for transportation by pipelines to refinery or market.

The pour point of the oil leaving line 34 is approximately 20 F., ormore, lower than the pour point of the oil leaving the pyrolysis step.This, of course, improves the pumpability of the oil also. These changesin the character of the oil are due directly to the cracking takingplace in the zone 30.

The balls, upon leaving the cracking zone, have an outlet temperature ofapproximately 800 to 1000'a F., i.e. 50 to 100 below their inlettemperature, and are returned along line 14 to the preheating step inzone 10, which has been previously described.

As mentioned previously, during the cracking of the oil vapors andgases, a substantial amount of coke is formed, as well as tarrysubstances. The amount of coke and tars produced ranges between 1% to 5%of the total oil vapors and gases. These substances would ordinarilydeposit on the walls of the cracking apparatus, such as a reactionchamber or a tube still, and eventually clog such apparatus. Further,When cracking in a tube still, the coke deposits on the walls of thestill greatly increase the temperature of these walls due to reducedheat transfer through the walls, and a failure of the tube wall due tooverheating can occur.

However, in my process the coke and tarry substances are deposited uponthe balls in the cracking zone to a far greater extent than on the wallsof the cracking equipment. The coke and tarry substances are thuscarried from the cracking Zone 30 by means of the balls themselves, theballs being sent to the preheating zone 10, as described.

Some cracking of the oil vapors and gases occurs in the pyrolysis Zone20 resulting in small amounts of coke and tar being deposited upon theballs in the pyrolysis phase of the process. However, it should beemphasized that the great bulk of the coke and tarry substances isdeposited during the cracking phase of the process in the cracking zone30, and is deposited upon the balls passing through the cracking zone atthis time.

The coke produced during the cracking phase of the process and depositedon the balls comprises substantially all combustible carbon, and thetarry substances cornprise generally speaking, heavy hydrocarbons andheavy nitrogen and sulfur-containing organic compounds. The coke can beburned to extract heat therefrom and increase the thermal eficiency ofthe process, while some of the tars can be removed, as will bedescribed, to further increase the yield of oil vapors and gases. Inthis regard, it is found that when the balls, having coke and tardeposited thereon, are introduced into the preheating zone l0 to beintimately admixed with fresh oil shale, the fresh oil shale, inaddition to being preheated by the balls, actually removes the bulk ofthe coke and tar from the balls by means of a rubbing, scraping orwiping action. The fresh oil shale is thus found to have a scouringeffect on the balls and effectively cleans the balls of substantiallyall the coke and tar deposited thereon in the pyrolysis and crackingsteps.

The clean balls are then led from the preheating zone 10, -along line22, to the ball heating zone 24, as previously described, and thepreheated oil shale, carrying the coke and tars, is sent to thepyrolyzing zone 20, via line 18, for the pyrolysis step.

Pyrolysis of the preheated oil shale occurs, as previously described,thereby resulting in the production of oil vapors and gases. The morevolatile tars, carried with the oil shale, are also pyrolyzedsimultaneously with the pyrolysis of the oil shale, thereby increasingthe total yield of oil. For purposes of this specification and theannexed claims, the volatile tars are defined herein `as those tars,deposited on the balls in the cracking apparatus, that are volatilizedor pyrolyzed under the conditions of pyrolysis previously described.

As is well known, a carbonaceous residue remains after oil shale ispyrolyzed, the carbonaceous residue from oil shale being hereinafterreferred to as carbonaceous shale residue. As has been mentioned, theoil shale originally was crushed to a smaller average mesh size than theballs, and the carbonaceous shale residue therefore has also a smalleraverage mesh size than the balls. In addition, during the pyrolysisespecially, the balls being composed of a hard, wear-resistingcomposition, crush and grind the oil shale into a substantially smalleraverage particle size than their initial size. Carbonaceous shaleresidue is thus readily separated from the balls by screening,elutriation `orother suitable methods, after `the pyrolysis. Thecarbonaceous shale residue produced during the pyrolysis leaves thepyrolyzing zone 20, via line 38, at a temperature lying betweenapproximately 750 to 950 F., and carries'with it the coke and thosetars, previously deposited on the balls in 4the cracking apparatus,which were not volatilized or pyrolyzed dur ing the pyrolysis step,these tars being hereinafter referred to as the non-volatile tars.

The carbonaceous shale residue, coke and non-volatile tars are then sentto a combustion step or zone 40 where they are combusted in the presenceof air or other free oxygen-containing gas thereby producing extremelyhot gases such as carbon monoxide and carbon dioxide as Well as hotsolid ash. The temperature of the hot gases and ash lies betweenapproximately 1200 to 1600 F. The heat from the products of combustion,that is, the hot gases and/or the hot ash, is transferred directly orindirectly to the balls in the ball heating zone 24 to thereby heat theballs to the desired temperature, which as stated previously rangesbetween 1000 and 1400 F. The hot gases and ash are sent to .the ballheating zone 24 along a common conduit 42, while the exhaust gases andcooled ash leave the zone 24 along the line 46 at a temperature lyingbetween approximately 550 and 900 F. The heated balls are then sent tothe pyrolyzing, cracking and preheating steps, `as described, and theprocess is repeated.

The air or other free oxygen-containing gas, employed for thecombustion, may be preheated by means of the hot exhaust gases and/orhot ash, -if desired.

It is also desirable to utilize the heat of the other products of thepyrolysis, or heat from extraneous sources, in some instances, for theheating of the balls.

A fresh ball inlet 47 and Worn ball outlet `48 are provided leading intoand out of line 22, respectively.

A specic example of the process shown .in FIGURE 1 (with no flow ofballs along line 27) follows:

One ton of minus 1A inch, twenty-five gall-ons per ton, oil shale, atapproximately 60 F., enters the preheating zone in a continuous streamto contact 1.4 tons of 5A; inch 960 F. aluminum-oxide containing ceramicballs, continuously entering the preheating zone Via line The oil shaleis thus preheated.

The preheated oil shale leaves zone 10 continuously via line 1S, at atemperature of about 505 F. and enters the pyrolyzing zone 20. The Watervapor driven 01T amounts to approximately 10% of the total waterpresent, and runs about two pounds for Colorado oil shale.

The balls leave the preheating zone 104 in a continuous stream at atemperature of 600 F., and are sent to the ball heating 4zone 24, alongline 22, for reheating. The balls yare reheated to a temperature of 1300F., by the products of combustion of the 'carbonaceous shale residue,and by the products of combustion of the Vcoke and non-volatile tarsproduced in Athe cracking zone 30 and produced to a Vsmall extent inpyrolysis zone 20. These 1300" F. balls are then iadmxed with thepreheated oil shale in the pyrolysis zone 20.

Approximately 200 pounds of oil vapors andlgases are formed during thepyrolysis land leave the zone at a temperature of 850 F., for thecracking zone 30 via line 28. The balls leave the pyrolyzing zone 20 ata temperature of 1000 Ff., fand are sent to the `cracking zone 30 wherethe oil vapors and gases contact the balls lfor a period of sixtyseconds. Y l

The oil vapors and gases are thus cracked and leave the zone 30, ata'tempe'rature of approximately 960 F., while the balls also leave thecracking zone at a temperature of approximately 960 F., and are returnedto the preheating zone 10 in a continuous stream, via line 14,

e for preheating fresh oil shale. Upon admixture of the balls with freshoil shale, the coke and tars previously deposited on the balls duringthe cracking are removed. Approximately 6 pounds of coke and tars aretransferred to .the fresh oil shale in this manner, and are brought intothe pyrolyzing zone 20.

During the pyrolyzing step, some of the tars are volatilized orpyrolyzed and approximately 1798 pounds of carbonaceous shale residue(containing approximatel)l 50 pounds of combustible carbon) are producedand leave zone 20, via line 38, at la temperature of 850 F. Also, thecoke and remaining tars leave with the carbonaceous shale residue forcombustion in zone 40. The hot gases and ash produced in combustion zone40 leave along line 42 at a temperature of 1400 F., and reheat the ballsin zone 24, as described.

The exhaust gases and ash leave the zone 24 via line 46 at a temperatureof approximately 800 F., and, by a heat exchanger (not shown) mayfurnish heat for the air used for combustion. rlhe air may thus bepreheated to a temperature of 500 F., prior to its entry into thecombustion zone 40, if desired, and to do so would allow extraction ofexcess heat from combustion zone 40- by air or steam cooling coils.

Mention has previously been mad-e that dust removal from the retortvapors and gases is accomplished to a great degree without the need foradditional equipment. It is found that the bulk of the dust entrainedfrom the pyrolyzing zone 20 along with the oil vapors and gases, iseectively removed from these oil vapors and gases in the cracking zone30 by means of contact with the ball stream moving through the :crackingzone. The dust is carried with the balls, via line 14, into thepreheating zone 10 in FIGURE 1.

While parallel flow of oil sh'ale and balls both in the preheating stepsand in the pyrolyzing steps has been described and is presentlypreferred, counterow of balls and oil shale, either in the preheatingstep or in the pyrolyzing step, or both, can also be utilized.

By means of the above-described cracking process, it is possible toreduce the pour point of the shale oil by about 15 F.

In order to increase the average inlet temperature of the balls enteringthe cracking zone 30, and thereby cause thermal cracking to occur athigher temperatures, a predetermined portion of the total number ofballs sent from the outlet line 25 of ball heating zone 24, is divertedinto the line Z7, and from thence passes into the cracking zone 30 vialine 32. Those balls passing along l-ine 27 `completely by-pass thepyrolyzing zone 20 and thus are not appreciably reduced in temperaturein going from the ball-heating zone 24 to the cracking zone 30.

It will be recalled that the ratio of balls to oil shale in the FIGURE 1embodiment, Without any by-pass of bal-ls via line 27, lies betwen 3:1'and 1:1, and is preferably -about 1.4: 1. When employing the bypassfeature, the ratio of balls to oil shale, passing through the pyrolysiszone 20, is still maintained betweenk 3:1 and 1:1, and is preferablysomewhat less than 1.441. The ball to shale ratio should preferably bemade somewhat smaller as the proportion of balls by-passed around thepyrol'ysis Zone 20 is increased, because the temperature of thepreheated -oil shale tends to increase with the increased by-passing dueto an increased ball temperature in line 14 from the cracking zone 30,as well as because of the increased ball to shale rat-io flowing intothe preheater zone 10. Indeed, it may in some cases be desirable toreduce the contact time of the oil shale with the balls in the preheaterzone Y 10 or to by-pass some of the balls around the preheating 7 thepyrolyzing zone 20, and that a preferred ball-shale ratio of l.25:1 isto be used in the pyrolyzing zone, the total ball toshale ratio willthen be approximately 1.56: 1.

'Ihe percentage of the total amount of balls in the system that can besent along by-pass line 27 varies from zero, as previously described upto approximately 50%. Thus, for a 50% ball `by-pass, the upper limit oftotal balls to shale is increased from lapproximately 3:1 to 6:1.

The amount of ball temperature increase produced by the utilization ofthe by-pass featu-re to its fullest extent is approximately 150 F. Thus,the temperature range of the balls entering the cracking zone 30 ofFIGURE l can vary from a low of about 850 F., to a high of about 1200 F.

In order to increase the average inlet temperature of the balls enteringthe cracking zone 30, by approximately 100 F., for example, from thehigh of 1050 F., previously described with a zero by-pass, to a high ofabout 1150 F., the total number of balls is iirst heated in zone 24 to atemperature approximately equal to l400 F., by contacting extremely hotgases and =ash at about l600 F., with the balls. The balls leave zone24, via line 25, and are split into two streams, one being sent, vialine 26, into the pyrolyzing zone 20, and the other being sent, via line27, into line 32, and thence into the cracking zone 30. A ball-oil shaleratio of 1.4:1 is maintained in the pyrolysis zone 20 and the ballsleave the pyrolyzing zone 20 at a temperature of 1050 F. Approximately30% of the total balls in the system enter the line 32 at a temperatureof 1400" F., and are admixed with the 1050 F., balls in line 32, or in asuitable mixing apparatus (not shown) placed in line 32. The combinedball stream, entering cracking zone 30, via line 32, has an averageuniform temperature of approximately l150 F.

The variation in the amount of by-pass of balls, via line 27, isaccomplished by conventional valve control means (not shown) placed inline 25. The valve control means is operatively controlled by theaverage ternperature desired in the bal-l stream las it enters thecracking zone 30.

As the temperature of the balls entering the cracking zone 30 increases,it is usually found that the period of cracking required decreases.Thus, las the temperature of the balls entering the cracking zone 3)increases from 1050 F., to 1150 F., the time of cracking may decreasefrom about 60 seconds to about 20 seconds, thus reducing the viscosityof the oil.

If a thermal cracking at still higher temperatures than previouslydescribed with reference to FIGURE 1 is desired, such a cracking step isIaccomplished at the desired high temperatures without losing any of theadvantages described with reference to FIGURE 1. Such a high temperaturecracking process is described in detail in FIGURE 2.

In FIGURE 2, balls used for the preheating of oil shale in preheatingzone 10a are sent to a ball heating zone 24a, of the type previouslydescribed in FIGURE 1, and after being heated to temperatures of betweenl150 and 1500 F., by the products of combustion, are sent directly, vialine 50a, to the cracking zone 30a. The extremely hot balls crack theoil vapors and gases entering the cracking zone 30a via line 28a, theballs, vapors and gases contacting each other either in coliow,counterow, cross-flow or other suitable manner.

It will be noted that the oil vapors and gases are cracked lby contactwith balls having a substantially higher upper temperature than thosepreferably employed in the cracking zone 30 of FIGURE 1. (Thetemperature of the balls entering the cracking zone 30 varied from 850F. to 1200 F.) Because the cracking in zone 30 occurs at such a hightemperature, the period of contact between the balls and oil vapors andgases is preferably extremely short, e.g., usually ranging between 1.0second and 20 seconds thus reducing the viscosity of the oil. The oilvapor and gas eiuent leaves zone 30a at a temperature of 950 to 1400 F.,via line 34a, and must be cooled immediately to 900 F., or lower, toprevent further cracklng.

The balls, after imparting their heat for the cracking step, have atemperature of about l000 to 1400" F., dropping about 50 to 200 F., inpassing through the cracking zone 30a. The balls are then sent directlyto the pyrolyzing zone 20a, via line 52a. The balls have coke and tardeposited thereon during the cracking process, as previously described.Practically all of the coke and tars are transferred to the incomingpreheated oil shale, and upon pyrolysis of the oil shale, is carriedwith the carbonaceous shale residue via line 38a to combusting zone 40a.

As mentioned previously, a small amount of cracking takes place in thepyrolysis zone 20 of FIGURE 1, and this is true also of the process ofFIGURE 2. During the cracking in the pyrolysis zone 20 or 20a, some ofthe coke and non-volatile tars produced are found to be deposited on theballs inasmuch as some cracking takes place on the balls which are thehottest surfaces in either of the pyrolyzing zones.

The balls, and the coke and non-volatile tars thus deposited thereon arethen transferred to the fresh, incoming oil shale, the balls and freshoil shale preferably being admixed in parallel ow. The fresh oil shaleacts to clean or scour the balls of the remainder of the deposited cokeand non-volatile tars, as previously described with reference toFIGURE 1. The coke and non-volatile tars eventually are sent to thecombusting zone 40o with the carbonaceous shale residue, as justdescribed.

It is thus seen that difficulties inherent in the coking phase of theprocess, due to the production of coke in the cracking chamber or zone30a, are effectively minimized by the provision of the circulatingheat-carrying bodies or balls. These balls directly contact the oilvapors and gases during the cracking phase of the process to therebypick up coke and tars produced in the cracking, and at some other pointin the process are admixed and agitated with oil shale. In this manner,substantially all the coke and tars are removed from the cracking zone30a and are transferred to the oil shale. Any coke and tars producedduring pyrolysis are also effectively removed from the system. Also, thebulk of the dust entrained from the pyrolyzing zone 20a, along with theoil vapors and gases, is effectively removed from these oil vapors andgases in the cracking zone 30a by means of contact with the ball streammoving through the cracking zone. The dust is carried with the balls,via line 52a, into the pyrolyzing zone 20a. It is thus seen that dustremoval from the oil vapors and gases is accomplished without the needfor additional equipment.

The remaining lines and zones of FIGURE 2 have been designated by thenumerals which correspond to the numerals aifixed to the correspondinglines and zones of FIGURE l, the numerals of FIGURE 2 also having theletter a added thereto. For example, the combusting Zone of FIGURE 2 isdesignated 40a, while the combusting zone of FIGURE 1 is designated bythe numeral 40. The temperature ranges of the materials flowing alongthese remaining lines and in the zones correspond to those of FIGURE 1in which there is no flow of balls along by-pass line 27.

It can thus be seen that the main difference between the continuousprocesses of FIGURES l and 2 is that the process of FIGURE 2 enables ahigh temperature cracking to take place, whereas the process of FIGURE lenables a lower temperature thermal cracking to occur. 'Ihe temperatureof the incoming cracking balls is thus seen to extend over a range offrom about 850 F. to 1050 F. (FIGURE 1 with zero by-pass), and fromabout 1050 F. to 1200 F. (FIGURE l with by-pass) and from about 1150 F.to 1500 F. (FIGURE 2), the total cracking temperature range thus lyingbetween about 850 F. and

9 1500 F. The temperature of cracking employed depends to a great extenton the type of stock being processed, as well as the products desired,and other factors. For example, if cracking takes place at the highertemperatures, more gas, unsaturated hydrocarbons, and aromatichydrocarbons and less saturated hydrocarbons are produced.

The ball to shale ratio can be varied in the process described inFIGURES l and 2. A ratio of 1.4:1 is presently preferred, althoughratios of from 3:1 to 1:1 have also been advantageously employed,depending on the ball temperature entering the pyrolyzing zones 20 or20a, and the degree of preheat supplied to the oil shale.

A specific example of the process described in FIGURE 2 follows: 1 tonof 25 gallon per ton oil shale enters the preheating zone a along theline 12a and is then admixed with 1.3 tons of balls having an inlettemperature of 800 F. to 900 F. Approximately 2 pounds of water vapor(for a particular Colorado oil shale) leaves along the line 16a. Thepreheated oil shale leaves the preheating zone 10a along the line 18a tobe sent to the pyrolyzing zone 20a. The oil shale now has a temperatureof about 505 F.

The balls leave the preheating zone 10a via the line 22a at atemperature of about 600 F., and are sent to the ball heating zone 24awhere they are reheated by means of hot combusted gas and shale ashentering the ball heating zone along the line 42a. The gases and ashhave a temperature of 1450 F. and heat the balls to a temperature ofl350 F. The exhaust gases and ash, leaving the ball heating zone 24a,along the line 46a, have a temperature of about 700 F. The reheatedballs are led from the ball heating zone 24a, along the line 50a, to thecracking zone 30a for the cracking of oil vapors and gases coming fromthe pyrolyzing zone 20a via line 28a.

The oil vapors and gases enter the cracking zone 30a at a temperature of850 F., and contact the 1350 F. balls for a period of live seconds. Thecracked oil vapors and gases leave the cracking zone 30a along the line34a at a temperature of 1150" F., and -are quenched immediately to atemperature below 800 F., to avoid any fur ther cracking.

The balls, in effecting the cracking of the oil vapors and gases, arereduced in temperature by approximately 100 F. They are sent then to thepyrolyzing zone along the line 52a at a temperature of l250 F.

The l250 F. ba-lls are admixed with the 505 F. oil shale in thepyrolyzing zone 20a thereby producing approximately 225 pounds of oilvapors and gases. These oil vapors and gases are sent to the crackingzone 30a and are cracked as just described.

Approximately 1773 pounds of carbonaceous shale residue are alsoproduced during the pyrolysis in zone 20a and -leave the pyrolyzing zonevia line 38a, along with some of the coke and tars that originally weredeposited on the balls in the cracking zone 30a. The carbonace'ous shaleresidue, coke and non-volatile tars are combusted in zone 40a and theirproducts of combustion leave the combustion zone via 42a, at atemperature of 1450" F., to reheat the balls 24a, as above described.

The balls leaving the pyrolyzing zone 20a, via the line 54a, have atemperature of about 960 F. They are sent directly to the heating zone10a to be admixed with fresh incoming oil shale, to thereby preheat theoil shale to 505 F., as described. The fresh oil shale also scours theballs of coke and tars deposited in the pyrolyzing zone 20a, `due to anycracking that occurs therein.

It will be noted that, while the ball and oil shale vstreams flowparallel to each other in the preheating step and in the pyrolyzingstep, the preheating -step and the pyrolyzing step lie in series withrespect to one another in the embodiments of FIGURES l and 2. Otherarrangements are possible and have been employed. For example, two rotating drums, instead of being employed in series, may each be employed asa pyrolyzing drum. No preheating drum is used in this embodiment of theprocess.

Fresh oil shale was introduced into each of the pyrolyz'- ing drumsplaced in tandem or in parallel. Heated balls were also introduced andthe oil vapors and gases p-roduced in each pyrolyzing drum were sent toa common cracking zone. The balls from each pyrolyzing zone werereheated and Sent to the cracking zone and eected the cracking of theoil vapors and gases therein. The balls, together with the coke and tardeposited thereon in the cracking zone, were then recycled to theparallel pyrolyzing steps where they -contacted fresh oil shale in eachof the pyrolyzing drums. The fresh oil shale removed the coke and tar asdescribed previously, and the more volatile tars were volatilized in thepyrolysis zones. The carbonaceous shale residue is removed from thepyrolyzing zone -along with the coke and non-volatile tars that wereinitially deposited upon the incoming balls, the coke, carbonaceousshale residue and the non-volatile tars being combusted to furnish heatfor the reheating of the balls. The reheating of the balls can takeplace just prior to the pyrolysis rather than after, as just described.

While the process just described is useful, the processes of FIGURES land 2 are preferable for a number of reasons set forth below.

In the preferred embodiments, FIGURES l and 2, most types of oil shaleare preheated to between 400 and 600 F., in a drum or zone separate fromthat of the pyrolyzing zone. It is found that the number ofheat-carrying bodies or balls required for bringing the oil shale to thedesired pyrolyzing temperature is substantially reduced when employing aseparate preheating step in comparsion to a proc* ess wherein the oilshale is both preheated and pyrolyzed `in a single zone, for the ballsmay be cooled through a greater temperature range during a given cyclein the process.

Also, at temperatures of between 400 and 600 F., it is found that aportion of the water of crystallization, as well as substantially all ofthe free moisture in the oil shale, is vaporized and leaves thepyrolysis zone 10 via line 16. It is advantageous to rid the oil shaleof as much water as possible in a separate zone prior to thepyrolyzation step, so that the amount of water vapor passing out withthe oil vapors and gases during pyrolysis is minimized. The amount ofwater vapor that is driven olf during the preheating is estimated to beapproximately 10% or more of the total free water and water ofcrystallization present in the oil shale.

The amount of water of crystallization in oil shale varies considerablydepending upon the origin and -location of the shale. For example,Brazilian oil shale is found to contain a much greater amount of waterof crystallization than Colorado oil shale, and the aforementionedpreheating step is especially advantageous when treating the Brazilianoil shale.

Further, the balls should be cleaned of coke and tars before they aresent to the ball heating zone 24 or 24a in order that the heattransferred to the balls be maximized. Coke and tars deposited on theballs are good insulators and would detriment-ally affect the transferof heat to the balls if they were retained thereon. Also, the heat ofcombustion of the coke and tars deposited on the balls appears to besomewhat more elciently transferred to the balls if the coke and tarsare rubbed off and eventually burned in the combustion zone 40 or 40a,than if they yare left on the balls and burned in the ball heating zone24 or 24a. The advantage of both FIGURES l and 2 over a process whereinthe pyrolyzing drums are in parallel, with the cracking taking placeafter pyrolysis, is that in FIGURES l or 2, the balls are cleaned ofcoke and tars prior to their entry into the ball heating zone 24 or 24a(by first passing through preheating zone 10 o-r 10a respectively); inthe parallel drum process, such cleaning 'cannot take place because theballs go directly from the cracking zone or pyrolysis zone to the ballheating zone.

Still further, in the parallel process, with cracking taking place afterthe pyrolysis, the volatile or pyrolyzable l 1 tars are burned ratherthan recovered in the oil vapors and gases, as in the processes ofFIGURES l and 2. Inasmuch as these tars generally contain valuablechemicals, it is economically wasteful to utilize them merely for theirfuel value.

Turning now to FIGURE 3, a modied form of process is shown wherein anoil shale preheating step is eliminated, and fresh oil shale is sentdirectly into a pyrolysis zone 109. Other refinements and Variations ofthe process are also shown and described.

Referring now to FIGURE 3, in detail, crushed oil shale at ambienttemperature, enters the pyrolysis zone or drum 100 along the conduit102. The oil shale may be preheated to approximately 300 F., by means ofWaste hot stack gases emanating from the cyclone 104 if desired.

In the pyrolysis zone 100, the oil shale is intermixed with larger-sizedhot balls, coming directly from the cracking zone 8, via line 110, andhaving a temperature of l050 to l450 F. The intermixing and pyrolysis isaccomplished with the ball and oil shale feed running concurrently inthe drum 100.

The oil and gas vapors produced in the pyrolysis zone 100 (which may beof a rotary drum or other suitable type) leave via line 110 at atemperature of 750 to 950 F. and pass countercurrently to the incomingballs and upwardly into the cracking zone 108, where the oil vapors andgases meet a continuous hot ball stream, which has an inlet temperatureof between ll50 and 1500" F., the exact temperature employed dependingon a number of factors, as has been previously mentioned.

The oil and gas vapors are thus cracked in the vapor phase, and withoutintervening condensation, in the presence of the hot ball stream, for apredetermined time, from 1.0 second to 60 seconds. The cracked oilvapors and gases, having a temperature of 900 to l200 F., areimmediately led to a condenser 111 via the line 112, and are immediatelycooled below approximately 800 F. to prevent further cracking.

The condensable oils leave via line 113, and the noncondensable gasesvia line 114.

Coke and tar are deposited on the balls in the cracking zone 108, aspreviously described with reference to FIG- URES l and 2, therebyavoiding clogging of the cracking equipment and overheating.

The coke and tars are rubbed or wiped off the balls by the action of thefresh oil shale in the pyrolysis zone 100. Here, it will be noted thatthe balls are cleaned in the pyrolyzing zone 100` rather than in apreheating zone 30. However, the removal of the coke and tars is stillaccomplished by means of oil shale. Upon pyrolysis of the oil shale andthe volatile tars, the resulting carbonaceous shale residue, coke andnon-volatile tars leave the pyrolysis zone 100, at a temperature ofbetween 750 to 950 F., passing into separating zone 116.

The smaller-sized carbonaceous shale residue, coke and tars pass throughthe openings 118 of screen 119 While the larger-sized balls having atemperature of between 850 and 1100 F., pass fro-m the separating unitor zone 116 directly into a conduit 124, where they are elevated to aball-heating zone 1246.

Gas locks 160, 162 of conventional type are interposed at the top ofcracking zone 108 and adjacent the separating unit 116, respectively.

The carbonaceous shale residue, coke and tars pass from zone 116 intoline 122 and thence into a fluidized combustion Zone 130, the air forcombustion of the carbonaceous shale residue entering along the line132. The air is preheated, as will be described, and allows recovery ofheat in the stack gases otherwise lost.

The combustion step is preferably, but not necessarily, conducted in ailuidized state. Other'suitable combustion processes, such as combustionin a packed bed or rotating bed of carbonaceous shale residue, can alsobe employed. The fluidized combustion step is preferable, however,inasmuch as the hard and wear-resistant balls grind the shale coke to aconsiderable degree in the pyrolysis zone 100. The amount of grindingoccurring is usually suicient to render the carbonaceous shale residueof a readily fluidizable size.

In order to readily control the temperature within the combustion zone130, and also to eiTect a greater heat economy, water or air isintroduced into a pipe 134, and is passed through coils 133 in the zone130, the amount of water or air introduced dictating the amount oftemperature lowering elected. Steam or preheated air leaves zone vialine 136 to be used elsewhere in the process or for other purposes.

The combusted gases produced in zone 130 leave the uidized zone 130 at atemperature of 1250" to 1600 F., along two conduits 138 and 140.Inasmuch as conduit 138 extends into the iluidized bed 142, the bulk ofthe hot ash produced in the zone 130 will be entrained, via conduit 138,within the hot combusted gases to the ball heating zone 126.

The remainder of the hot combusted gases pass upwardly through conduit140, and pass through downwardly moving hot balls in a hot ball inletchamber 144 and hot ball outlet passage 146 communicating therewith. Inthis manner, substantially all the shale ash entering the inlet chamber1414 with the balls is blown back into the ball heating zone 126.

It will be recalled that the balls enter the zone 126 from the line 124,the balls coming directly from pyrolysis zone 100 at a temperature ofbetween 850 to 1100 F. The balls preferably enter the top of the ballheating zone 126, which, in some instances, may merely be an uppersection of a combustion zone, and move downwardly countercurrently tothe upwardly moving hot gases and entrained ash. Coflow of balls, gasesand ash or other suitable methods of direct contact can also beemployed. The heated balls are directed into outlet passage 146 by meansof an inclined screen 150, and thence flow into the cracking zone 108,at a temperature of ll50 to l500 F., for the cracking of oil vapors andgases, as described.

The `combusted gases and ashes, after passing through the ball heatingzone 126, pass through overhead conduit 152 at a temperature of between900 to l400 F., thence into a heat exchanger 154 where air, at ambienttemperature, enters heat exchanger 154 along line 156 to be preheated,for the combustion, to a temperature of between 500 and l200 F. Thepreheated air passes along line 132 to the combustion zone 130, aspreviously described.

The combusted gases and the ash, after having passed through heatexchanger 154, pass along conduit 157 at a temperature of 500 to 1200F., and are separated in one or more cyclones, the stack gas leavingalong line 106, and the ash along line 160. The stack gas, having a 600to 800 F. temperature, can be used to preheat the fresh oil shale, asnoted previously.

A ball bleed-olf line and a fresh ball inlet line 172 are also providedleaving and entering the ball elevator line 124, respectively. Theball-shale ratio can be varied within the same limits described withrespect to FIGURES 1 and 2.

A specific example of -the process shown and described with reference toFIGURE 3 follows: One ton of fresh 25 gallon per ton oil shale entersthe pyrolysis zone 100 along the line 102, at ambient temperatures, andcontacts hot balls entering the pyrolysis zone 100 from the line 110,the balls having a temperature of 1350 F., and a flow rate adjusted togive a ball to shale ratio of approximately 2.3:1.

The balls come into the pyrolysis zone 100 directly from the crackingzone 108 and have approximately 6 pounds of coke and tars depositedthereon which are scrubbed off by the fresh oil shale in the pyrolysiszone 100, in the manner described previously with reference to FIGURE 1.

The inlet oil shale size in minus one-quarter mesh,

whereas the ball diameter is approximately Vs inch. During the pyrolysisin the pyrolysis zone, the average size of `the oil shale issubstantially reduced, approximately 75 percent of the oil shale havingan outlet mesh size of less than l mesh. While such a reduction in sizeinevitably produces a larger amount of dust, this dust is not sent tothe cracking zone along with the oil vapors and gases because it iscaught by the balls and carried downwardly with the balls into thepyrolysis zone 100. An efficient dust removal system is thusincorporated into the process as an integral part thereof without theneed forl the usual dust -removal equipment.

Approximately 200 pounds of o il vapors and gases, and volatile tarsproduced during the pyrolysis are sent to the cracking zone 103 for thecracking thereof, as will be described. Approximately 1810 'pounds ofcarbonaceous shale residue, coke and non-volatile tars are separatedfrom the balls in unit 116 and arev sent to a combustion zone 1730 viathe line 122, the carbonaceous shale residue, coke and tars having aninlettemperature of 850 F. The total amount of free combustible carbonthus sent to the combustion zone 130 is approximately 56 pounds.

Airenter's the combustion zone along the line 132 at a temperature of530 F. with a sutlicient velocity to tluitliae theresidues in zone 130and combustion takes place so that the outlet gases and ash have atemperature 'of l400 F. Water or air enters the conduit 134, passesthrough the coils 133 within the Combustion zone and leaves as steam orpreheated air along line 136. In this manner, the combustion within thecombustion zone is controlled so that the outlet temperature of thecomb'ustion products is maintained within relatively close limits. Thebulk of the shale ash produced during the combustion leaves along theline 138 with the majority of the hot combustion gases and passesthrough a downwardly moving packed bed of balls in the ball heating zone126. The remainder of the hot gases passes upwardly through linep140 fora purpose to be described.

It will be recalled that the balls separated from the earbona'ceousshale residue, coke and tar within separating unit 116 pas'slthrough theball elevator line 124, at a temperature of 900 F. and enter the ballheating zone 126. The balls are thus reheated by means of the hotcombusted gases and the shale ash to a temperature of 1375 F. The hotash and gases, leaving the ball heating zone 12o via ythe line 152, havea temperature of 950 F. and are sent to a heat exchanger 154 where theypreheat air to a temperature of 530 F. The preheated air is sent Vialine 132 to the combustion zone 130 for the combustion of carb'onaceousmaterial as previously described.

The reheated balls, having va temperature of 1375" F. pass into conduit146 and into ball inlet chamber 144. The balls carry with them the hotash previously sent to the ball heating zone 125 via the line 138. Thehot combusted gases entering the chamber 144 from the line -140 removeor sweep the ash from the balls and from the chamber. the cracking zone108, contacting vapors at 850 F. l'entering the 'cracking zone via line110. Cracking is eiiected over a period of time of l5 seconds.

The `cracked oil vapors and gases leave the cracking zone 108 along theline 112 to be immediately quenched in the condenser 111. The crackedoil vapors and gases have a temperature of 1175 F. prior to thequenching -and are quenched to at least 800 F. so that further The hotballs, at l375 F. then enter l It will thus be seen that a highlyefficient process is provided for the pyrolyzing and cracking of oilshale and the like, in that the condensing and reheating of the oill andgas vapors prior to cracking is eliminated.

Furthermore, the coke and t'ar deposited on the balls in the crackingzone 108 eliminates the possibility of clogging and overheating of thecracking equipment. The coke and tars arey carried out with the ballstream, through the pyrolysis drum 100, and eventually the coke and thenon-volatile tars pass through the combustion zone with the carbonaceousshale residue. The coke andr non-volatile tars thereby furnishadditional heat for the process in a simple, continuous andtroublefreemanner.

Also, dust problems in the oil vapors and gases are greatly reduced,inasmuch as the bulk of the dust entrained from the pyrolysis dru'm 100by means of the oil vapors and gases is led back by the ball stream tore-enter the pyrolysis drum via conduit 110.

It will be seen that a plurality of separate and distinctnon-intermingling ball 'circiuts can be utilized, if desired. Forexample, a separate ball vcircuit between the pyrolyzing zone, ballheater and 'oil shale preheating zone, and a second circuit between thecracking zone and a separate ball heater can be employed.

Also, it will be understood that portions of the reheated or relativelycool ball streams could be utilized for preheating air 'for' combustionpurposes, preheating water for steam, as well as the other usespreviously described.

It should b'e noted that the temperature of the oil vapor 'and gasefuent from the cracking zones 30, 30a and 108 of FIGURES 1, 2 and 3,respectively, can readily be varied between about 825 F. and 140() F.

Attention is also drawn to the fact that in some instances, all or partof theheat required for heating the balls in any of the embodiments ofmy process may be furnished from sources extraneous to the process, orby means of the products of pyrolysis other than the carbonaceous shaleresidues, e.g., the combustible gases.

While several embodiments of my invention have been disclosed herein, itwill be understood that modifications and changes may be made hereinthat lie within the ordina'ry skill of those in the art. For thisreason, I do not intend to be bound by the embodiments `herein shown anddescribed, but intend to be bound only by my claims which follow.

-I claim: v

1. The process of obtaining oil 'and gas, from solid material leaving,upon pyrolysis, a solid carbo'naceous residue, which comprises the stepsof: pyrolyzing said solid material by` solid-to-solid milling contactwith solid heat-carrying bodies to obtain oil vapors and gases, and aAsolid carbo'naceous residue; separating said heat-carrying bodies yfromsaid solid carbonaceous residue, produced upon the pyrolysis of saidsolid material; thermally cracking, in a separate zone, said oil vaporsand gases by admixtnre with said separated lsolid heat-carrying bodiesto obtain cracked oil vapors and gases; combusting said solidcarbonaceous residue to thereby produce heat in the form of gaseous andsolid products; reheating the solid heat-carrying bodies yby means of atleast one of said .products of combustion;v and recycling said heatedheatcarrying bodies for admixture with additional solid material for thepyrolysis thereof, and for the cracking of oily vapors and gasesproduced during said pyrolysis.

2. The process of claim 1 wherein said solid material and theheat-carrying bodies are admixed in parallel flow during pyrolysis.

3. The lprocess of claim 1 wherein said solid material is oil shale. K

`4. The process of claim l wherein said solid material -iis oil shaleand the temperature of said solid heat-carrying bodies employed for thecracking of said oil vapors and gases lies between 850 F. and 1500 F.

5. The process of claim 1 wherein said solid carbonaceous residue isiluidized and the combustion thereof takes place in a iluidized state.

6. The process of claim 1 wherein coke and tars produced during saidcracking are deposited on said heatcarrying bodies which furnish theheat for said cracking, said coke and non-volatile component of the tarsbeing later combusted, along with said carbonaceous residue, to furnishadditional heat to the process.

7. The process of claim 1 wherein oil vapors and gases, and entraineddust therein, are passed through said separated heat-carrying bodies, asubstantial amount of said entrained dust being collected on saidbodies.

8. The process of claim 1 wherein said heat-carrying bodies employed inthe pyrolyzing and cracking steps are intermixed with fresh solidmaterial in a separate zone to thereby preheat said solid material, to atemperature of below 700 F., prior to its pyrolysis.

9. The process of obtaining oil and gas from solid material, leaving,upon pyrolysis, a solid carbonaceous residue, which comprises:pyrolyzing said solid material by solid-to-solid milling contact withhot, solid heatcarrying bodies larger than said carbonaceous residue toproduce an oil vapor and gas effluent and a solid carbonaceous residue;separating said heat-carrying bodies from said solid carbonaceousresidue, produced upon the pyrolysis of said solid material; thermallycracking,in a separate zone, said oil vapor and gas eiliuent by means ofsaid heat-carrying bodies in the absence of said carbonaceous residue toproduce a cracked oil vapor and gas eiuent, said heat-carrying bodieshaving a substantially dilierent initial temperature for the crackingthan for the pyrolysis; combusting said separated carbonaceous residuein the presence of an oxygen-containing gas to thereby produce heat inthe form of hot gaseous and solid products; reheating said heat-carryingbodies employed in the pyrolysis and cracking steps by means of at leastone of said products of combustion; and recirculating said reheatedheat-carrying bodies for admixture with additional solid material andresulting oil vapors and gases for said pyrolysis and cracking steps.

l0. The process of claim 9 wherein the initial temperature of saidheat-carrying bodies immediately prior to the cracking, is higher thanthe initial temperature of said heat-carrying bodies immediately priorto the pyrolysis.

11. The process of claim 9 wherein the initial temperature of saidheat-carrying bodies immediately prior to the cracking, is lower thanthe initial temperature of said heat-carrying bodies immediately priorto the pyrolysis,

12. The process of claim 9 wherein the temperature of said oil vapor andgas eflluent from the pyrolysis lies between 750 to 950 F. and thetemperature of said cracked oil vapor and gas eluent from the crackinglies between 825 and l400 F.

l13. A continuous process for obtaining oil and gas from solid material,leaving upon pyrolysis, a solid carbonaceous residue, which comprises:pyrolyzing said solid material, by solid-to-solid milling contact withhot heat-carrying bodies larger than said solid carbonaceous residue, toproduce oil vapors and gases and solid carbonaceous residue, theheat-carrying bodies being partially cooled thereby; separating saidheat-carrying bodies from said solid carbonaceous residue, produced uponthe pyrolysis of said solid material; thermally cracking, in a zoneseparated from said solid material and said solid carbonaceous residue,said oil vapors and gases, prior to the condensation thereof, in thepresence of said separated partially cooled heat-carrying bodiesemployed in the pyrolysis to produce thereby still cooler heat-carryingbodies; combusting said solid carbonaceous residue in the presence of afree oxygen-containing gas to thereby produce heat in the form of hotgaseous and solid products; reheating said cooler heat-carrying bodiesby means of at least one of said products of combustion; and recyclingsaid reheated heat-carrying bodies for admixture with additional solidmaterial and resulting oil vapors and gases for said pyrolyzing andcracking steps, said resulting oil vapors and gases being kept separatefrom said combustion gases.

14. The process of claim 13 wherein the temperature of the oil vaporsand gases, immediately after cracking lies between 825 F. and 1000 F.,and temperature of oil vapors and gases immediately after pyrolysis liesbetween 750 F. and 950 F.

l5. The process of claim 13 wherein said solid material is preheatedjust prior to pyrolysis, the temperature of the solid material after itspreheating ranging between 400 to 700 F., the heat for said preheatingbeing furnished by at least a portion of said cooler heat-carryingbodies.

16. The process of claim 13 wherein coke and tars produced during saidcracking are deposited on said heatcarrying bodies which furnish heatfor said cracking, said coke and the non-volatile component of the tarsbeing later combusted, along with said solid carbonaceous residue, tofurnish additional heat to the process.

17. The process of obtaining oil and gas from oil shale which comprises:preheating fresh oil shale in a preheating zone to a temperature ofbetween 400 and 600 F. by solid-to-solid milling contact of said oilshale in parallel flow with partially cool heat-carrying bodies largerthan the preheated oil shale, said partially cool bodies having atemperature higher than said fresh oil shale; reheating said partiallycool heat-carrying bodies; pyrolyzing said preheated oil shale bysolid-to-solid milling contact, in parallel flow, with said reheatedheatcarrying bodies, to produce oil vapors and gases having atemperature ranging between 750 and 950 F., and carbonaceous shaleresidue; separating said heat-carrying bodies from said carbonaceousresidue; thermally cracking, in a zone separated from said solidmaterial and said solid carbonaceous residue, said oil vapors and gases,prior to the condensation thereof, in the presence of said separatedheat-carrying bodies having an initial temperature of between 850 and1050 F., coke and tars produced during said cracking being deposited onsaid separated heat-carrying bodies; returning said heat-carrying bodiesfrom the cracking zone to said preheating zone for the preheating offresh additional oil shale, thereby partially cooling the heat-carryingbodies and, by contact, transferring the coke and tars from saidheat-carrying bodies to said fresh oil shale, the volatilization of thevolatile tars, as well as production of said oil vapors and gases,occuring during saidpyrolysis, said coke and the non-volatile componentof the tars being carried with said carbonaceous shale residue formedduring the pyrolysis; combusting said carbonaceous shale residue, cokeand tars in the presence of a free oxygen-containing gas to therebyproduce hot gaseous and solid products, said reheating of said partiallycool heat-carrying bodies being provided by means of at least one ofsaid products of combustion for the preheating of additional fresh oilshale.

18. The process of obtaining oil and gas from oil shale, leaving uponpyrolysis, a carbonaceous shale residue, which comprises: pyrolyzingpreheated oil shale by solidto-solid milling contact thereof with hotterheat-carrying bodies having an initial temperature of between 1000 to1400 F., to produce oil vapors and gases at a temperature of between 750and 950 F. and carbonaceous shale residue in a pyrolysis zone;separating said heat-carrying bodies from said carbonaceous shaleresidue, produced upon the pyrolysis of said oil shale; transferringsaid heat-carrying bodies employed in the pyrolysis of said preheatedoil shale with fresh oil shale to a preheating zone to thereby preheatsaid oil shale to a temperature of between 400 and 600 Ff., theheat-carrying bodies being partially cooled after said preheating;combusting said carbonaceous shale residue produced during the pyrolysisto produce hot gaseous and solid products; reheating said partiallycooled heat-carrying bodies -by means of at least 'one of said productsof combustion to a temperature of between 1000 and l400 F.; contactingsaid reheated heat-carrying bodies with said oil vapors and gases, in 'azone separate from said pyrolysis Zone, to effect cracking of said oilvapors and gases, the coke and tars produced during' the cracking beingdeposited on said heat-carrying bodies; adrnixing said heat-carryingbodies employed in the cracking, along with coke and tars producedduring lthe cracking, with said preheated oil shale `for the pyrolysisthereof, said coke and tars being removed from the heatcarrying bodiesand taken along with said carbonaceous shale residue produced during thepyrolysis to be combusted to furnish additional heat for the process.

19. The process or obtaining oil and gas from o-il shale, leaving uponpyrolysis, a carbonaceous shale residue, which comprises: pyrolyzing oilshale by solid-tosolid milling contact with hotter larger-sized,heat-carrying bodies having aninitial temperature lying between l050 F.and 1450 F., said oil shale and heatecarrying bodiesbeing admixed inparallel now, oil vapors and gases and carbonaceous shale residue beingproduced during said pyrolysis; separating said heat-carrying bodiesfrom said carbonaceous shale residue; fluidizing said carbonaceous shaleresidue; combusting said iluidized carbonaceous shale residue to producegaseous and solid hot products; reheating said heat-carrying bodies bydirect contact thereof with at least one of said hot combustionproducts; contacting said r'eheated heat-carrying bodies with said oilvapors and gases to thereby crack said oil vapors and gases, coke andtars produced during the cracking being deposited on said heat-carryingbodies; and admixing said heat-carrying bodies carrying said coke andtars, with additional oil shale, said coke and tars being removed fromsaid heat-carrying bodies by said additional oil shale, and the coke andtars being carried out with said carbonaceous shale residue producedduring the pyrolysis of said oil shale, said coke and nonvolatile tarsbeing combusted with said shale coke to furnish additional heat for theprocess.

20. The process according to claim 19 wherein said products ofcombustion include -both hot gaseous products and hot entrained shaleash, said products of combustion being divided into two streams, onestream comprising the bulk of the entrained ash and a substantial amountof the hot gaseous products produced, said one stream being admixed withsaid heat-carrying bodies forv the reheating of saidl bodies, and theother stream comprising substantially the remainder of the hot gases,being admixed with said heat-carrying bodies after they have beenreheated by said one stream, said other stream removing substantiallyall of the shale ash collected by the heat-carrying bodies..

2l. Apparatus-for continuous recovery of oil from oil shale comprising:a preheating rotary drum having an inlet for fresh oil shale and anoutlet for preheated oil shale; a pyrolyzing rotary drum having an inletfor preheated oil shale, an outlet for carbonaceous shale residue and anoutlet for oil vapors and gases, said carbonaceous shale residue andsaid oil vapors and gases resulting from pyrolysis of said preheated oilshale in said pyrolyzing drum; a plurality of solid heat-carrying bodieslarger than the preheated oil shale; a heater for heating said bodies;means for moving said carbonaceous shale residue to a combustion zone;means for combusting said carbonaceous shale residue in said combustionzone to provide heat for said heater; means for moving said heatcarryingbodies from said heater into and through said `pyrolyzing drum inparallel flow therethrough with said preheated oil shale, from saidpyrolyzing drum into and through said preheating drum in parallel flowtherethrough with said fresh oil sha1e,and from said preheating druminto 'and through said heater; means assoeiated with said preheating4rotary drinn for' separating 'said heat-'carrying bodies from thepreheated oil shale; and means associated `with the pyrolyzing rotarydrum for separating said heat-carrying bodiesv from said lcarbonaceousshale residue.

22. Apparatus for continuous recovery of oil from oil shale comprising:a preheating rotary drum having an inlet for fresh oil shale and anoutlet Ifor preheated oil shale; a pyrolyzing rotary drinn having aninlet for preheated oil shale, an outlet -for carbonaceous shale residueand an outlet for oil vapors and gases, said carbonaceous shale residueand said oil vapors and gases resulting from pyrolysis of said preheatedoil shale in said pyrolyzng drum; a plurality of 'solid heat-carryingbodies larger than the preheated oil shale; a heater for heating saidbodies, said heater comprising means for cornbusting said carbonaceousshale residue and transferring lthe heat from at least one of theproducts of 'said cornbustion to said heat-carrying bodies to therebyheat said bodies; means for moving said heat-'carrying'bodies from saidheater into and through said pyrolyzing drinn in parallel howtherethrough with said preheated oil shale, from said pyrolyzing druminto and through said preheating drum in parallel ow therethrough withsaid -fr'esli oil shale, and from said preheating drum into and throughsaid heater; means associated with said preheating rotary drum forseparating said heat-carrying bodies from the preheated oil shale; meansassociated with the pyroly'zing rotary drum for separating saidheat-carrying bodies from said carbonaceous shale residue; and means forpassing said oil vapors and gases from said pyrolyzing drum through acracking chamber in contact =with said heatcarrying bodies during thepassage of said heat-carrying bodies between said heater and saidpreheating dru'n.

23. Apparatus for continuous recovery 'of oil from oil shale comprising:a preheating rotary drum having 'an inlet for fresh oil shale and anoutlet for preheated oil shale; a pyrolyzin'g rotary drum having aninlet for preheated oil shale, an outlet for carbonaceo'us shale residueand an outlet for oil vapors and gases, said carbonace'ous shale residueand said oil vapors and gases resulting from pyrolysis of said preheatedoil shale in said pyrolyzing drum; a plurality of solid heat-carryingbodies larger than the preheated oil shale; a heater for heating saidbodies; means for moving said heat-carrying bodies from said heater intoand through said pyrolyzin'g drum in parallel ow therethrough with saidpreheated oil shale, from said pyrolyzing drum into and through saidpreheating drum in parallel ow therethrough with said fresh oil shale,and from said preheating drum into. and through said heater; meansassociated with said preheating rotary drum for separating saidheat-carrying bodies from the preheated oil shale; means associated withthe pyrolyzing rotary drum for separating said heat-carrying bodies fromsaid carbonaceous shale residue; and means for passing said oil vaporsand gases from said pyrolyzing drum through a cracking chamber incontact with said heatcarrying bodies during the passage of saidheat-carrying bodies between said heater and said pyrolyzingl drum.

24. Apparatus for continuous recovery of oil from oil shale comprising:a preheating rotary drum having an inlet for fresh oil shale and anoutlet for preheated oil shale; a pyrolyzing rotary drum having an inletfor pre heated oil shale, an outlet for carbouaceous shale residue andan outlet for oil vapors and gases, said carbonaceous shale reside andrsaid oil vapors and gases resulting from pyrolysis of said preheatedoil shale in said pyrolyzing drum; `a plurality of solid heat-carryingbodies larger than the preheated oil shale; a heater for heating saidbodies; means for moving said heat-carrying bodies from said heater intoand through said pyrolyzirig drum in parallel ow therethrough with saidpreheated oil shale,- from said pyrolyzing drum into and through saidpreheating drum in parallel ow Itherethrough with said fresh oil shale,and from said preheating drum into and through said heater; meansassociated with said preheating rotary drum for separating saidheat-carrying bodies from the preheated oil shale; means associated withthe pyrolyzing rotary drum for separating said heat-carrying bodies fromsaid carbonaceous shale residue; and means for passing said oil vaporsand gases from said pyrolyzing drum through a cracking chamber incontact with said heatcarrying bodies during the passage of saidheat-carrying bodies between said pyrolyzing drum and said preheatingdrum.

25. The apparatus of claim 24 wherein means is provided for bypassingsome of said heat-carrying bodies around said pyrolyzing drum into saidcracking chamber.

26. A plant for the continuous recovery of oil from oil shalecomprising: a pyrolyzing rotary drum having an inlet for oil shale, anoutlet for carbonaceous shale residue and an outlet for oil vapors andgases, said carbonaceous shale residue and said oil vapors and gasesresulting from pyrolysis of said oil shale in said drum; a plurality ofheat-carrying bodies larger than the carbonaceouse shale residue; aheater for heating said bodies; means for moving said heat-carryingbodies from said heater into and through said pyrolyzing drum and backto said heater; means associated with said pyrolyzing rotary drum forseparating the heat-carrying bodies from the carbonaceous shale residue;and means for passing said oil vapors and gases from said pyrolyzingdrum through a cracking chamber in contact with said heat-carryingbodies to thermally crack said oil vapors.

27. A plant for the continuous recovery of oil from oil shalecomprising: a pyrolyzing rotary drum having an inlet for oil shale, anoutlet for carbonaceous shale residue and an outlet for oil vapors andgases, said carbonaceous shale residue and said oil vapors and gasesresulting from pyrolysis of said oil shale in said drum; a plurality ofheat-carrying bodies larger than the carbonaceous shale residue; aheater for heating said bodies; means for moving said heat-carryingbodies from said heater, into and through said pyrolyzing drum and acracking Zone, and back to said heater; means associated with saidpyrolyzing rotary drum for separating the heat-carrying bodies fromthe'carbonaceous shale residue; and means for passing said oil vaporsand gases from said pyrolyzing drum through said cracking chamber incontact with said heatcarrying bodies .to thermally crack said oilvapors.

28. A process for the continuous recovery of oil from oil shale whichcomprises: preheating fresh oil shale to a temperature of between 400and 700 F. by admixing said oil shale in parallel ow, in solid-to-solidmilling contact with solid hotter heat-carrying bodies having a particlesize larger than that of the preheated oil shale, said heat-carryingbodies being partially cooled thereby; separating said partially cooledheat-carrying bodies from the preheated oil shale; heating saidpartially cooled heatcarrying bodies; pyrolyzing said preheated oilshale by admixture in parallel ow, with said heated heat-carrying bodiesto lproduce oil vapors and gases, and carbonaceous shale residue;separating said heat-carrying bodies from the car-bonaceous shaleresidue; thermally cracking a portion of the said oil vapors and gases;and combusting said carbonaceous shale residue to produce hot productsof combustion, said products of combustion furnishing the heat for thesaid heating of said heat-carrying bodies.

29. The process of obtaining oil and gas, from solid material, leaving,upon pyrolysis, a solid carbonaceous residue, which comprises the stepsof: pyrolyzing said solid material to produce oil vapors and gases and asolid carbonaceous residue; thermally cracking, in a zone separated fromsaid solid material and said solid carbonaceous residue, said oil vaporsand gases, heat for -both pyrolyzing and cracking being provided byadmixture of said solid material and said oil vapors and gases,respectively, with solid hot heat-carrying bodies having a particle sizelarger than the said carbonaceous residue, said heat-carrying bodies andsaid solid material being in solid-to-solid milling contact duringpyrolysis of said solid material and being separated from said solidmaterial and said carbonaceous residue before being contacted with saidoil vapors and gases; reheating said solid heat-carrying bodies; andrepeating said pyrolyzing and cracking steps by admixture of additionalsolid material and resulting oil vapors yand gases with said reheatedsolid heat-carrying bodies.

30. The process of obtaining oil and gas, from solid material, leaving,upon pyrolysis, a solid carbonaceous residue, which comprises the stepsof: pyrolyzing said solid material to produce oil vapors and gases and asolid carbonaceous residue; thermally cracking said oil vapors andgases, in a zone separated from said solid material and said solidcarbonaceous residue, heat for both pyrolyzing and cracking beingprovided by admixture of said solid material and said oil vapors andgases, respectively, with solid heat-carrying bodies, said heatcarryingbodies being larger than said carbonaceous residue; separating saidsolid heat-carrying bodies from said carbonaceous residue; reheatingsaid solid heat-carrying bodies; at least part of the heat beingfurnished by means of at least one of the products of combustion of thesaid carbonaceous residue; and repeating said pyrolyzing and crackingsteps by admixture of additional solid material and resulting oil vaporsand gases with said reheated soild heat-carrying bodies, saidheat-carrying bodies and solid material being in solid-to-solid millingcontact during pyrolyzing of said solid material.

31. The process of claim 30 wherein said heat-carrying bodies employedin the pyrolyzing and cracking steps are inter-mixed with fresh solidmaterial in a separate zone to thereby preheat said solid material, to atemperature of below 700 F., prior to its pyrolysis.

32. The process of claim 30 wherein only part of all of said reheatedheat-carrying bodies contact additional solid material for the pyrolysisthereof.

33. The process of obtaining oil and gas, from solid material leaving,upon pyrolysis, a solid carbonaceous residue, which comprises the stepsof: pyrolyzing said solid material by solid-to-solid milling contactwith solid heat-carrying bodies larger than the said solid carbonaceousresidue to obtain oil vapors and gases, and a solid carbonaceousresidue; separating said heat-carrying bodies from said solidcarbonaceous residue, producedupon the pyrolysis of said solid material;thermally cracking said oil vapors and gases, in a zone separated fromsaid solid material and said solid carbonaceous residue, by admixturewith said separated solid heat-carrying bodies to obtain cracked oilvapors and gases; combusting said solid carbonaceous residue to therebyproduce hot gaseous and solid products; reheating all Vof said solidheat-carrying bodies by means of at least one of said products ofcombustion; and recycling part of said heated heat-carrying bodies -foradmixture with additional solid material for the pyrolysis thereof andrecycling part of said heatcarrying bodies for the cracking of oilvapors and gases produced during said pyrolysis.

34. The process of claim 33 wherein said heat-carrying bodies employedin the pyrolyzing and cracking steps are intermixed with fresh solidmaterial in a separate zone to thereby preheat said solid material, to atemperature of below 700 F., prior to its pyrolysis.

References Cited in the tile of this patent UNITED STATES PATENTS1,450,327 Smith Apr. 3, 1923 1,940,955 Laird Dec. 26, 1933 2,027,862Goodwin et al Jan. 14, 1936 (Other references on following page) 21UNITED STATES PATENTS Ostergaard Nov. 6, 1945 Dutcher Dec. 5,1950 RexAug. 26, 1952 Johnson et al. Nov. 9, 1954 5 22 Jahnig et al. Jan Iahniget al Jan Burnside et al. Feb

Russell Apr. Krebs et a1 Aug

1. THE PROCESS OF OBTAINING OIL AND GAS, FROM SOLID MATERIAL LEAVING,UPON PYROLYSIS, A SOLID CARBONACEOUS RESIDUE, WHICH COMPRISES THE STEPSOF: PYROLYZING SAID SOLID MATERIAL BY SOLID-TO-SOLID MILLING CONTACTWITH SOLID HEAT-CARRYING BODIES TO OBTAIN OIL VAPORS AND GASES, AND ASOLID CARBONACEOUS RESIDUE, SEPARATING SAID HEAT-CARRYING BODIES FROMSAID SOLID CARBONACEOUS RESIDUE, PRODUCED UPON THE PYROLYSIS OF SAIDSOLID MATERIAL, THERMALLY CRACKING, IN A SEPARATE ZONE, SAID OIL VAPORSAND GASES BY ADMIXTURE WITH SAID SEPARATED SOLID HEAT-CARRYING BODIES TOOBTAIN CRACKED OIL VAPORS AND GASES, COMBUSTING SAID SOLID CARBONACEOUSRESIDUE TO THEREBY PRODUCE HEAT IN THE FORM OF GASEOUS AND SOLIDPRODUCTS, REHEATING THE SOLID HEAT-CARRYING BODIES BY MEANS OF AT LEASTONE OF SAID PRODUCTS OF COMBUSTION, AND RECYCLING SAID HEATEDHEATCARRYING BODIES FOR ADMIXTURE WITH ADDITIONAL SOLID MATERIAL FOR THEPYROLYSIS THEREOF, AND FOR THE CRACKING OF OIL VAPORS AND GASES PRODUCEDDURING SAID PYROLYSIS.